This invention relates to a feed tray assembly in a fiber processing machine which forms a fiber lap (fiber batt), for example, from wool or chemical fiber tufts. The machine includes a fiber feeding device composed of a slowly rotating feed roll cooperating with a feed tray. A rapidly rotating opening roll is disposed immediately downstream of the feed roll (as viewed in the direction of fiber advance). The fiber feeding device and the opening roll withdraw the fiber material from a reserve chute and forward the material to a downstream-arranged device for processing the fiber material. The feed tray assembly includes a feed tray array formed of a plurality of individual feed trays rotatable about an axis.
In a known device of the above-outlined type as disclosed, for example, in German Offenlegungsschrift (application published without examination) 34 13 595, in a fiber tuft feeder for a card, above the opening roll which separates the upper chute (reserve chute) from the lower chute (feed chute), a feed roll is disposed which draws the fiber tufts from the upper chute in cooperation with a feed tray array which is composed of a plurality of closely side-by-side arranged individual feed trays. Each feed tray is pivotal about an axis which extends parallel to the feed roll axis. The individual feed trays are pivoted by the fiber tufts to an extent which depends from the mass of the fiber tufts passing through the gap defined by the feed trays and the feed roll. The feed trays are situated at the outlet of the upper chute. The support shaft on which all the individual feed trays are mounted extends beyond the two flanking (outermost) feed trays and is disposed in the narrow, air-impervious side walls of the reserve chute.
It is a disadvantage of such a prior art arrangement that the tray-supporting shaft which extends throughout the width of the tuft feeder, sags so that it cannot be used in case of wide roller card feeders which may have a width of over 3 m. It is a further drawback that the distance between the individual feed trays, on the one hand and the feed roll, on the other hand, is altered in an undesired manner. Further, the pressing forces urging the feed trays against the feed roll are not uniform which may lead to changes or misalignments of the clearance between adjoining feed trays, likely to cause operational disturbances. It is a further disadvantage of the prior art arrangements that the feeding device cannot be adapted to different types of fiber material, particularly different fiber lengths.